These little temp gauges can be found on Amazon or eBay for under 10 dollars.
The hardest part was finding finding a good spot to feed it through the floor.
On the passenger side, just below the radio, I was able to pull down the carpet and drill a 1/4 inch hole.
Don't go too deep. There are sensitive parts down there.
Of the two trans cooler lines on the transmission, the top one is the outlet to the cooler. I zip tied the tip of the temp probe to that line and wrapped it in some rubber insulation.
